Configuration Partitioning

The Configuration Partitioning feature provides modularization (“partitioning”) of the running configuration state to provide granular access to the running configuration in Cisco IOS software.

This feature is enabled by default in Cisco IOS software images that include this feature.

The configuration state of a device is retrieved dynamically whenever a user issues the showrunning-config command. When the Configuration Partitioning feature is enabled, the system groups the configuration state of the device into parts (called “partitions”) so that only the configuration state the user wishes to review is retrieved when generating a displayed list of commands in the running configuration. This feature improves performance for high-end systems with complex configurations because only a part of the running configuration state is processed when generating the running configuration command list, as opposed to the existing method of processing the entire system configuration state.

Default configuration partitions are provided by the introduction of this feature; other Cisco IOS software features may define their own command partitions in later releases.

Finding Feature Information

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Information About Configuration Partitioning

System Running Configurations

Managing the configuration of any Cisco IOS software-based device involves managing the startup configuration (startup-config), which is a file stored in nonvolatile memory, and the running configuration (running-config), which is the set of all configuration options currently in effect on the system. Typically, the startup configuration file is loaded when the system boots, and changes to the system’s running configuration, applied using the command-line interface (CLI), are saved by copying the running configuration to a configuration file (either locally or on the network), which can then be used to configure the device at startup, or used to configure other devices.

Retrieving the Running Configuration for Display or Copy Operations

In the Cisco IOS software configuration model, the configuration state is maintained in a distributed manner, with each component storing its own configuration state. To retrieve global configuration information, the software must poll every component to collect the distributed information. This configuration state retrieval operation is performed by a process known as nonvolatile generation (NVGEN), and it is invoked by commands such as showrunning-config, which is used to display the current configuration state, and copysystem:running-configuration, which is used to save the running configuration by copying it to a file. When invoked, the NVGEN process queries each system component, each interface instance, and all other configured component objects in a standard sequence. A running configuration file is constructed as NVGEN traverses the system performing these queries, and it is this “virtual file” that is displayed or copied.

Benefits of Partitioning the Running Configuration

The Configuration Partitioning feature is the latest in a series of Configuration Generation Performance Enhancement Features for Cisco IOS software. (See the “Related Documents” section for related features.) This feature improves the system’s response time by providing a method for querying only the system component you wish to review when issuing the showrunning-config command.

When the Configuration Partitioning feature is enabled, the system groups the configuration state of the device into parts (called “partitions”) for the purpose of generating the virtual running configuration file (the list of configuration commands). A new command, showrunning-configpartition, allows you to display only the part of the running configuration that you want to examine, rather than having to display the entire running configuration at once, or displaying only lines that match a certain string.

The key benefit of this feature is that it increases system performance by allowing the system to run the NVGEN process for only the collection of system components (such as specific interfaces) that you need to display. This is in contrast to other existing extensions to the showrunning-config command, which only filter the generated list after all system components have been processed.

The selective processing of the system’s configuration state for the purpose of generating a partial running configuration is called “configuration partitioning.”

More granular access to configuration information offers important performance benefits for high-end routing platforms with very large configuration files, while also enhancing configuration management by allowing advanced configuration features to be implemented at a more granular level. Advanced configuration options include Cisco IOS software support for provisioning of customer services, Config Rollback, Config Locking, and configuration access control.

How to Use the Configuration Partitioning Feature

Displaying Configuration Partitions

The main method of taking advantage of this feature is by using the showrunning-configpartitionpartcommand in priveledge exec mode, which is a specialized extension to the showrunning-configcommand.

Note

The partitionpart command extension is not available for the more:systemrunning-config command.

Because this feature offers improved performance for existing commands, this feature is enabled by default in Cisco IOS software images that support this feature. To quickly determine if this feature is supported and running on your system, issue the showrunning-configpartition? command in privileged EXEC mode.

SUMMARY STEPS

1.showrunning-configpartition?

2.showrunning-configpartitionpart

DETAILED STEPS

Step 1

showrunning-configpartition?

Issuing this command will show you the list of running configuration parts available for display on your system.

If the Configuration Partitioning feature is supported on your system and is enabled, you will see the string “ config partition is TRUE ” as the first line of help output.

If you receive an error message when entering the command syntax shown here, this feature is not supported on your system. See the command documentation for the showrunning-config command for existing extensions of that command in other releases that allow you to show only part of the running configuration.

Note

The list of available configuration parts may vary by software image and is dependent on what features are currently configured.

Choose the part of the running configuration you want to display, and use the associated keyword as the part argument in Step 2.

Step 2

showrunning-configpartitionpart

As an example, to have the system perform the NVGEN process on only the components associated with the access-list parts of the running configuration state, and display only the access-list related configurations, you would enter the showrunning-configpartitionaccess-list command:

This command also allows you to run the NVGEN process and display the resulting output for specific interfaces. This is a key capability of this feature, as it was designed for systems with numerous active interfaces.

In the following example, the main configuration partition is the interface configuration, and the specific part of the configuration to be generated is the configuration for Fast Ethernet interface 0/0.

Disabling the Configuration Partitioning Feature

Because this feature offers improved performance for existing commands, this feature is enabled by default for Cisco IOS software images that support this feature. However, you may want to disable this feature if you determine that it is not needed, as this feature does use a small amount of system resources (memory and CPU utilization). To disable configuration partitioning, perform the following task, which assumes you are starting in user EXEC mode.

SUMMARY STEPS

1.enable

2.configureterminal

3.noparserconfigpartition

DETAILED STEPS

Command or Action

Purpose

Step 1

enable

Example:

Router> enable

Enables privileged EXEC mode.

Enter your password if prompted.

Step 2

configureterminal

Example:

Router# configure terminal

Enters global configuration mode.

Step 3

noparserconfigpartition

Example:

Router(config)# no parser config partition

Example:

Disabling config partitioning

Example:

Router(config)#

Disables the configuration partitioning feature.

What to Do Next

What to Do Next

To reenable the feature after it has been disabled, use the parserconfigpartition command in global configuration mode.

Note

As this feature is enabled by default, only the no form will appear in the running configuration file, or will be written to the startup configuration file when you issue the copyrunning-configstartup-configcommand.

Configuration Examples for Configuration Partitioning

This section provides examples of displaying configuration partitions with the showrunning-configpartition command:

Displaying Configuration Partitions Example

In this example, the showrunning-configpartitioncommand is used with related commands in a series of steps an administrator might take to check the status of a specific interface and the current configuration of some of the system’s other components. Comparable filtered output from the standard showrunning-configcommand (for example, showrunning-config|includeaccess-list) is included for demonstration purposes.

Note

The part argument can consist of multiple partition name keywords, as in showrunning-configpartroutereigrp1.

1 The “Configuration Logger Persistency” feature allows saving just the commands entered since the last startup-config file was generated, rather than saving the entire startup configuration.

Standards

Standard

Title

No standards are associated with this feature.

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MIBs

MIB

MIBs Link

No new or modified MIBs are supported by this feature, and support for existing MIBs has not been modified by this feature.

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RFCs

RFC

Title

No new or modified RFCs are supported by this feature, and support for existing RFCs has not been modified by this feature.

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Description

Link

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Feature Information for Configuration Partitioning

The following table provides release information about the feature or features described in this module. This table lists only the software release that introduced support for a given feature in a given software release train. Unless noted otherwise, subsequent releases of that software release train also support that feature.

Use Cisco Feature Navigator to find information about platform support and Cisco software image support. To access Cisco Feature Navigator, go to www.cisco.com/​go/​cfn. An account on Cisco.com is not required.

Table 1 Feature Information for Configuration Partitioning

Feature Name

Releases

Feature Information

Configuration Partitioning

12.2(33)SRB 12.2(33)SB 12.2(33)SXI

The Configuration Partitioning feature provides modularization (“partitioning”) of the running configuration state to provide granular access to the running configuration in Cisco IOS software. This feature is enabled by default in Cisco IOS software images that include this feature.

In 12.2(33)SB, this feature was implemented on the Cisco 10000 series.